Flow actuated switch



Petente e? "1 f Nathaniel Beewesfg Fisehee t Portel @emi Elevation etfemisyimmis,

finalisation etei'iee lillo lieviti The present inveiitioe relates tomeasuring strwnenteD and it relates mere partieiileriy to flow metersand to automatic aies-nis foi' flow mete-irs and other measuringinstuixlents.

in object oi the present invention is te ptoifitie e inexoensive,sensitive, and, dependable s "we les* meestal-mg instruments. Anether'ebje' @i the present invention is te previo@ eigmeelnenism wllieh Wilisutometieelly leI spoed when e variable coneiition drs-ps below oi risesSleeve e predetermined value. Still moti obiect of the present inventionis lte premie meelieeism which will eutometieally respond te efiesumcient flow-l'etes en@ which is sii-Kiera sensitive to permitpractical installes time and deiiendeble operation. A furthe? obje-et elthe present invention is to provide meellansm W will automaticallyrespond te excessive el insumeient {flow-rates enti which will not giveeee-- onclery es' false responses.

Other olijeete and advantages et the present invention me apparent inthe following deteileel description, claims and aeeempanying drawings.

For the purpose of illustlating the inventien, there shown in thesoeompenyieg drawings ene tomi thereof which is ei; present pieierreei,slnee the has been found in preetiee to setisfeetesy emi reliableresults, although it ie te he understood that the various instemmenmilities el, which the invention censists een be vez'ieuely arrenged andorganized and that @lie wltion is not limited to the preeise etrange senti olganizations of the instrumenteiities es herein shown anddesoxiiaefi Referring to the eeeompenying drawings .in Widen likerei-ermee ehereetei's intimate lllize parte throughout:

Figure 1 represents e view, pestly in elevation and partly in vertieaieross-eectiefil of elle emn bodimeait of the present invention.

Figure 2 represents e vertical cross-sectional view on en enlargedseale, showing the signalling mechanism es it appears in eiosed oreneieto ing poeition.,

Figure 3 represents a, side elevational View ot the mercury switchforming peri; of the signalling mechanism o Figure 2, as it appetite imits normal open position.

Figure 4i represents e, perspective View et auxiliary magnet clame.

Figure 5 represents e side elevational View @i the mercury switch tekengeneraily et eight en gies to the view ef @iwi-e In the embodiment ofFigures 1 to a. vee ticaiiy extending downwardly-tapered metering timewhich mey lie et glass or synthetic plastie el etilei: suiteblemateriel, has its upper end held in flinwtiglii; sealing relationshipwith an upper outlet ttine il by ineens of peeking rings I2 and stunggland i3 and has its lower end simllefly "nele in iiuid=tigl1t settlingrelationship with e lewe?,- inlet fitting M by means of packing :tinget5 e, stuffing gland i5. The fitting Il ieee e eemiuit ii omied thereinleading from the lippe? emi et tlie metering tube it! and terin eneutlet opening i8 to which an outlet pipeline te is adapted to beconnected.

The loweff: inlet fitting M is provided with a conduit leetii'lig; iiomthe lower end of the metering tube iii anni te'minatng in an inletoenine 2t' te Wmel'i. en inlet pipe-line 22 is eeeetecl be eminente@ Theinlet ottime i@ also contains an opening wieieii eonneets with e.downwardly extending tulle neitl le. fistltieht sealing relationshipwith seid titties i@ by' means of packing rings 25 enel et stellinggland 2S; the tube 24 being eleseti its lewet enel.

A meteine; :Fleet 2 having e now-constricting 52@ is eeeptee". for freetip-middelen l metering" tube i0; the posi-i @oet 2i Within the taperedmeting ireteof-tlow of fluid movie@ moers-diy l eilen said tube i0 in amam nel" well lirios-m in the mt.

tuee il@ extends downwardly from the meterfleet iy til-lenen theeonneoting opening 23 in inlet fettine l@ and into the closed tube Theextensie@ tube 2s is oeseci at its lower .in which pes-itioned a. barmegnet 30 havine sentii pele et the bottom and its north pole tile telo.A layer of sealing wax 3l within said extension tube 29 provides a,4Huid-tight seal ier seriell magnet Sti., The magnet 3i! may be ofLagiietiezed item oi suitable iron alloy, such as Ktiniest Tile tunes;2e end 25 may be mede of glass or etliei eoiteiile ilowmegnetiemateriali.

le meenetieelly-aetuated indicating mecha mism te be describedhereinbelow is carried by a. freine Sii which is mounted upon the tube24 and which is eeiepted to be moved vertically along Selci tolse te.,

The indicating mechanism includes s, sealedglass meieurySwlteheindicated generally by the reference eneiaeter 33. The switch 33is provided with e smell weil 34 eontainine' a bead of memory i intesielectrode 38 extends downwardly from E the top the switch 33 and intothe mercury bend (l5.

.en arm il is mounted in the top of the switch and supports one end of aSpiral hair spring the other end oi which extends downwardly andterminates in a plate or flag 39 oi iron or the like which is sensitiveto magnetism. Extending generally horizontally from the lower edge orthe flag is a wire 40, the other end of which terminates in a generallyvertically extending mov able electrode 4l. The horizontal wire 40 issupported intermediate its ends by a looped rod 42 descending `from thearm 37.

1n its normal position, the switch 33 is open; the movable electrode 4lbeing held clear of the mercury bead 35 as shown in Figure 3. When,however, suiilcient magnetic attraction is brought to bear on the lefthand side of the switch, the nag moves toward the left in Figure 3against the tension of the spiral spring 38 and carries with it themovable electrode 4i so that said movable electrode enters the mercurybead 35 and closes the electric circuit. The upn per end of the hiredelectrode 35 and the upper end oi the arm 3l (which .is in electricalconnection with the movable electrode 4l through the spring 38, the dag3B and the wire 4B) pass through the wall oi the switch 33 and areconnected to wires 43 and 44 respectiveiy, which, in turn connect withany suitable electric circuit having any suitable audible and/or visualalarm (not shown).

rfi clamp 45, shown in Figure 4, is adapted to be removably positionedabout the switch 33 and to be fastened to the frame 32, by means ofbolts A pair of small bar magnets 46 of iron or Alnico or the like areconnected to the clamp and are supported thereby at the left hand edgeof the switch 33.

The north poles of the magnets 4S are placed in line with the dag 35i;the south poles oi said magnets 45 being above and out of line with saidIn operation, the frame 32 may be located upon the tube 2d so that asignal may be given to indicate either excessive or insufficientrate-oliiow.

is stated hereinabove, the position of the metering float 2l within themetering tube i0 is dependent upon the rate-o-ovv of fluid upwardlythrough the tube l; the greater the rate of flow the higher the positionof the ioat and vice versa. It is obvious that, as the float moves, itcarries with it the extension tube and the large bar magnet 3U.

l'i' the signalling device is to be used to indicate insumcient iiowrates, the frame 32 is so positioned upon the tube 24 that, in thepredetei'mined minimum position of the iloat 27 the north pole of thelarge bar magnet 3l) will be in alignment with the north poles of thesmall magnets 46 and with the :lag 39 as shown in Figure 2.

When the rate-of-iiow of fluid is normal, that is above thepredetermined minimum the float 2l will be in an elevated positionwithin the metering; tube iii and the large bar magnet 3U will also beabove the position shown in Figure 2.

During such normal operation the switch 33 is open; the small magnets 4Sbeing insulcient in strength to move the ilag 3S.

-Whem however, the rateofflow drops below the predetermined value, thelarge magnet 3D moves downward until its north pole is in horizontalalignment with the north poles of the small magnets 46. In this positionthe magnetic force oi the magnets is additive and is suillcient toattract the flag 39 and thereby to move the electrodo 4i into themercury bead 35 and thus to close the switch 23 and to actuate the alarmmechanism. Should the rate-of-flow increase thereafter, the meteringfloat 2l will rise within the tube i0 and carry the large magnet 30 outof alignment with the mercury switch 33, whereupon the spring 38 willmove the ilag 39 and the electrode 4l back to their original positionagainst the insunicient attraction of the auxiliary magnets 4B, therebyto re-open the switch.

While it has been suggested in the past to use a magnetically-actuatedmercury switch of the general character of the switch 33 in connectionwith moving magnet to operate an alarm, the construction of the presentinvention, utilizing as does small auxiliary magnets in addition to themagnet, has several important advantages over conventional alarms.

Thus for example, it has been found in practice that where no small'auxiliary magnets are employed, it is impossible to get satisfactoryoperation or" the mercury switch unless the flag of the switch is veryclose to the main magnet; the practical limit being approximately Vg".Since the combined thickness of the walls of the tubes 24 and 29,together with the necessary clearance between these tubes exceeds 1/8",conventional magnetically-actuated switches were found to be unreliablein operation.

By employing the novel auxiliary magnets (which themselves are too Weakto close the mercury switch) of the present invention, this difdculty isovercome since the additive force of the combined north poles of themain magnet and of the auxiliary magnets is suicient to actuate the flag39 and thereby to close the mercury switch at distances several timesthose heretofore attainable.

Another disadvantage of alarms heretofore used was that the flag 39(being magnetically neutral) would be attracted by the south pole of themagnet es well as by the north pole. Thus, every time the main barmagnet passed the mercury switch, two impulses would be created, one asthe south pole passed the flag and the other as the north pole passedthe nag. 'I'his double impulse was undesirable since one of the two is afalse alarm so that any one hearing or seeing the alarm mechanism go olfcould not be sure, without going over to inspect the flow meter itself,whether or not the flow-rate had dropped below the predeterminedminimum.

By the present construction this double im pulse is eliminated since, asthe south pole of the main magnet passes the mercury switch its magneticeld is diverted from the flag 39 by the north poles of the auxiliarymagnets so that the mercury switch is not closed. Similarly, since thesouth poles of the auxiliary magnets are above and out of line with thenag, the ilag is not actuated when the south pole of the main magnetpasses the south poles of the auxiliary magnets.

It can, therefore, be seen that the present construction gives adependable and unmistakable signal and permits clearances which arerequired for practical operation.

It is obvious that the frame 82 can be moved vertically along the tube24 to position the switch and auxiliary magnets at any desired point.Thus, the mechanism can be adjusted to sound atc an alarm at anypredetermined minimum value of dot-vante.

It is also obvious that the mercury switch can be positioned near thetop of the tube 24 to indicate excessive now-rates; the north pole oithe main magnet closing the mercury switch when the oat 21 rises to apredetermined level Within the metering tube i0.

It is also possible to employ two separate switches, one positioned nearthe bottom oi the tube 2d and the other positioned near the top oi thetube 2t, to actuate separate alarm mech*u anlsrns and thus to indicateboth excessive and insumcient flow-rates.

While for purposes of illustration the ioregoing description refers tothe north poles of the auxiliary magnets as being in line with the "llaait is obvious that the reverse could be true. 'iii-iat is, the auxiliarymagnets t could be reversed so that their south poles are in line withthe das titl and so that the north poles are above the i'iag. In thiscase, the flag 39 would be moved and the switch 33 would be closed whenand only when the south pole of the main magnet iil came into verticalalignment with the south poles ci' the auxiliary magnets 4t and with thein niece oi, or in addition to, the alarm mechanism hereinabovereferred, to, it is possible to incorporate valve means into theelectrical circuit controlled by the mercury switch 3d. Thus, anyconventional valve means could be conheated, ior example, to the inletpipedine t2, and could be arranged vertically to open upon inusudicientiiotvrate or to close upon excessive dow-rate in place oi, or inaddition to, the alarm mechanism. 1

While 'the novel actuating mechanism of the present invention has beendescribed in connection with a flow meter wherein it constitutes apreferred embodiment, it is obvious that the present invention is notlimited to this einbodiu ment. Thus, for example, the mercury switch,auxiliarymagnets and main magnet construction of the present inventioncould be used in conn nection with any other measuring instrument whichproduces a movement of the main. magnet upon change in a. variablecondition, such as temperature, pressure, etc.

Instead of having the closed tube 2d and the extension tube 29 extenddownwardly from the losveriitting ift as described hereinabove, it ispossible to have these elements extend upward-u ly by merely reversingthe ttine's Il and M, making the fitting Il the inlet fitting and, thesitting i4 the outlet fitting. extension tube would extend upwardly fromthe top of the rotameter iioat instead of downwardly from the bottomthereof. The use of metering iioats having either upward or downwardexten sions is well known in the rotameter art and is shown, #forexample, in my (zo-pending application, Serial No. 498,443, filed August13, 1943.

The present invention may be embodied in other specific forms withoutdeparting from the sont or essential attributes thereof, and lt istharefore desired that the present embodiment be considered in allrespects as illustrative and not restrictive, reference being had to theap pended claims rather than to the foregoing description to indicatethe scope of the invention.

Having thus described the invention, what i claim as new and desire toprotect by Letters Patn ent, is:

1. `For use with an instrument sensitive to a variable condition. amagnet, means connected to in such case, the

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instrument for moving said magnet respon sive to variation in saidcondition, switch means including; a magnetically-actuated make-andbreakelement disposed adjacent the path of travel of said magnet, and anauxiliary magnet having one pole disposed adjacent said matze-and-abreai element, the pole of said auxiliary magnet alonehaving insufdclentstrength to actuate said mahe-and-break element, but together with thealigned similar pole oi the mst-mentioned magnet being capable ofactuating said rnaie-and-break mechanism.

For use with an instrument sensitive to a variable condition, a magnet,means connected to said instrument for moving said magnet responsive tovariations in said condition, switch means includingmagnetically-actuated make-andbreals element disposed adjacent the pathof travel ci said magnet, and an auxiliary magnet having one noiedisposed adjacent said makeand-brealz element, the pole of saidauxiliary magnet alone having insuicient strength to actuate saidmalre-and-break element, but together with the aligned similar pole ofthe first-mentioned magnet being capable of actuating saidmalte-and-brealr mechanism, said pole of said auxiliary magnet tendingto divert the field of the aligned opposite pole of the first-mentionedmagnet thereby to prevent actuation of the makeand-brealz element bysaid opposite pole.

3. For use with a dow-meter, a magnet, means connected to saidflow-meter for moving said magnet responsive to variations inrate-of-iiow, switch means including a magnetically-actuatedmalte-andbreah element disposed adjacent the path of travel of saidmagnet, and an auxiliary magnet having one pole disposed adjacent saidmakehandmbreak element, the pole of said auxillary magnet alone havinginsuicient strength to actuate said makewandmreak element, but togetherwith the aligned similar pole of the rstmentioned magnet being capableof actuating said niale-and-break mechanism.

d. For use with a, dow-meter, a magnet, means connected to saidfiow-meter for moving said magnet responsive to variations iniate-of-ow, switch means including a magnetically-actuatedmairemarid-breal element disposed adjacent the nath of travel of saidmagnet, and an auxiliary magnet having one pole disposed adjacent saidmake-and-breaia: element, the pole of said auxiliary magnet alone havinginsuiiicient strength to actuate said make-andbreak element, but togather with the aligned similar pole of the rstmentioned magnet beingcapable of actuating said maite-andbreal mechanism, said pole of saidmagnet tending to divert the field of the aligned opposite pole of thefirst-mentioned magnet thereby to prevent actuation of the makeandbreakelement by said opposite pole.

5. in combination with a rotameter having a vertical metering tube and ametering iioat adapted for free up-and-down movement within fr. ou

said tube, an elongated member connected to said float and extendingvertically therefrom beyond said metering tube, a bar magnet disposed atthe iree end of said elongated member, an electrical switch having amagnetically-actuated movable contact element disposed adjacent the pathof travel of said magnet, and an auxiliary magnet having one poledisposed adjacent said movable contact element, the pole of saidauxiliary mag net alone having insuicient strength to actuate saidmovable contact element but together with. the aligned similar pole ofthe first-mentioned 7 magnet being capable of actuating said movablecontact element.

6. in combination with a rotameter having a vertical metering tube and ametering oat adapted for free up-anddown movement within said tube, anelonagted member connected to said float and extending verticallytherefrom beyond said metering tube, a bar magnet disposed at the freeend of said elongated member, an electrical switch havinf7 amagnetically-actuated movable contact element disposed adjacent the pathoi travel or" said magnet, and an auxiliary'magnet having one poledisposed adjacent said movable contact element, the pole of saidauxiliary magnet alone having insucient strength to actuate said movablecontact element but together with the aligned similar pole of themst-mentioned magnet being capable oi actuating said movable Contactelement, said pole of said auxiliary magnet tending to divert the fieldof the aligned opposite pole of the iirst-mentioned magnet thereby toprevent actuation of the movable Contact element by said opposite pole.

7. n combination with a rotameter having a vertical metering tube and ametering lloat adapted for free up-and-clown movement within said tube,an elongated member connected to said and extending vertically therefrombeyond said metering tube, a bar magnet disposed at the .free end oisaid elongated member, an electrical switch having amagnetlcally-actuated movable contact element disposed adjacent the pathof travel of said magnety and an auxiliary magnet having one poledisposed adjacent said movable contact element, the pole of saidauxiliary magnet alone having insufllcient strength to actuate saidmovable contact element but together with tbe aligned similar pole oftne first-mentioned magnet being capable of actuating said movableContact element, seid electrical switch together with its auxiliarymagnet being vertically adjust able along the path of travel of saidErst-mentioned magnet to permit actuation of said movable contactelement at any predetermined rateofni'l NATHANLEL BREWER.

REFERENCES CITED The following references are of record in the le of'this patent:

UNITED STATES PATENTS Number Name Date 2,307,304 Rudd Jan. 5, 1943594,323 Carpenter Nov. 23, 1897 1,527,932 Sperry Feb. 24, 1925

